Castro was released by the Athletics on Thursday.

EDGE Analysis

Castro has thrown 54 innings in his big-league career, recording a 4.50 ERA. He'll look to latch on with another organization on a minor-league deal and could provide pitching depth in the minors but is unlikely to be much of a fantasy asset.

Castro agreed to a minor-league deal with the Athletics on Thursday that includes an invitation to spring training, Susan Slusser of the San Francisco Chronicle reports.

EDGE Analysis

Simon signed a minor-league deal with the A's last offseason and split his time between Triple-A Nashville and the majors in 2017. He was effective in the minors (3.32 ERA over 38 innings) but less so in the bigs (4.38 ERA over 37 innings). He could work his way on to the Opening Day roster with a strong spring training performance.

Castro was outrighted to Triple-A Nashville on Monday, Susan Slusser of the San Francisco Chronicle reports.

EDGE Analysis

Castro saw plenty of time in the majors during the 2017 campaign. He pitched 37 innings over 26 games and finished the year with a 4.38 ERA and 1.24 WHIP. His control was lackluster, as he owned a 35:14 K:BB and gave up home runs at a lofty 1.7 HR/9 clip. Moving forward, Castro's fantasy value is fairly limited, as his performance to this point hasn't warranted use in high-leverage situations.

Castro allowed two earned runs on three hits over two-thirds of an inning in Monday's 8-3 win over the Tigers.

EDGE Analysis

Castro was the first of a parade of relievers called upon following emergency starter Raul Alcantara's exit after 3.2 innings. The hard-throwing right-hander disposed of James McCann to finish out the fourth, but ran into trouble in the fifth by allowing RBI doubles to JaCoby Jones and Ian Kinsler. The results were par for the course for Castro, who's now surrendered a pair of earned runs apiece in each of his last three appearances and in four outings overall in the last five. Castro's rough stretch has bumped up his ERA from 2.88 to 4.55, even as he's generated an impressive nine strikeouts over 8.1 innings over that span.

Castro fired two scoreless innings in Tuesday's 8-2 loss to the Angels, allowing one hit and three walks. He struck out two.

EDGE Analysis

The hard-throwing right-hander's fina line represented a much-needed bounce-back from the four earned runs he'd surrendered over his previous trio of appearances. Castro did issue multiple free passes for the first time this season, but he also recorded multiple whiffs for the third straight outing. Despite his recent stumbles, his solid 3.09 ERA, 1.03 WHIP and 21 strikeouts over 23.1 innings are helping keep him relevant in deeper formats.

Castro (1-2) gave up a game-winning solo home run for his only hit and earned run over two-plus innings in Wednesday's 8-7 extra-inning loss to the Orioles. He also issued a walk and recorded three strikeouts.

EDGE Analysis

Castro otherwise turned in a dominant 33-pitch appearance, but his one mistake against Manny Machado cost the Athletics the game. The 29-year-old right-hander has been scored upon in three straight appearances and allowed a total of four earned runs over the five innings encompassing that stretch. Despite the recent stumbles, Castro's ERA and WHIP remain a solid 3.43 and 0.95, respectively, thanks to his performances earlier in the season, but he's trending in the wrong direction as of late.

Castro worked a scoreless seventh inning in Monday's 6-2 loss to the Royals, allowing a hit and a walk.

EDGE Analysis

The hard-throwing reliever has mostly been dominant over his last 10 appearances, giving up three runs (two earned) over 14.1 innings while generating a .143 BAA and allowing a .182 wOBA. Castro's stuff would appear to be nasty enough for a potential closer's role, something manager Bob Melvin could opt to experiment with before the season concludes.

Castro fired 2.1 scoreless innings in Sunday's 6-5 extra-inning win over the Twins, allowing a hit and a walk while recording three strikeouts.

EDGE Analysis

Castro has posted back-to-back scoreless efforts of at least two innings, allowing just a hit and a walk while notching five strikeouts. The 29-year-old right-hander boasts a wicked mid-90s fastball that affords him significant strikeout upside and that could lead to some closing opportunities, given Santiago Casilla's inconsistencies in the ninth-inning role.

Castro fired two scoreless innings in Saturday's 6-3 loss to the Twins in which he recorded two strikeouts.

EDGE Analysis

The 29-year-old right-hander has looked particularly impressive in his last two outings, working three scoreless frames overall and allowing just one hit. Castro offers elite strikeout upside -- as evidenced by his 63 whiffs over 38 innings with Triple-A Nashville prior to his recent call-up -- so he could certainly stick in what has been an inconsistent Athletics bullpen that recently lost two of its most trusted arms in Sean Doolittle and Ryan Madson.

The Athletics selected Castro's contract from Triple-A Nashville on Sunday.

EDGE Analysis

Castro will join the Athletics for what's likely a temporary basis to provide an extra arm out of the bullpen after relievers Sean Doolittle and Ryan Madson were traded to the Nationals on Sunday. The Athletics did take back another bullpen arm in Blake Treinen back in the deal, so once Treinen joins the big club, Castro could be shipped back to Triple-A. Over 38 innings with Nashville this season, the 29-year-old has supplied a 3.32 ERA to go with an eye-popping 63 strikeouts.